Storage unit and control system

ABSTRACT

A storage unit coupled to a controller for receiving a first control signal and a second control signal is provided. The storage unit includes a cell array, a first access module and a second access module. The cell array stores data. The first access module accesses the data stored in the cell array according to the first control signal. The second access module processes the data stored in the cell array according to the second control signal to generate a search result and provides the search result to the controller. When the first access module receives the first control signal and the second access module receives the second control signal, the first and second access modules simultaneously operate.

CROSS REFERENCE TO RELATED APPLICATIONS

This Application claims priority of Taiwan Patent Application No.102140823, filed on Nov. 11, 2013, the entirety of which is incorporatedby reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a storage unit, and more particularly to astorage unit which is capable of providing specific data.

2. Description of the Related Art

Storage units are usually applied in electronic devices to store data.The storage units comprise volatile memories and non-volatile memories.The volatile memories comprise random access memories (RAMs), dynamicrandom access memories (DRAMs) and static random access memories(SRAMs). The non-volatile memories comprise read-only memories (ROMs),programmable read-only memories (PROMs), erasable programmable read-onlymemories (EPROMs), electrically erasable programmable read-only memories(EEPROMs), and flash memories.

Generally, when an external controller desires to retrieve specific datastored in a storage unit (e.g. maximum data), since the externalcontroller does not know the address corresponding the specific data,the external controller cannot provide the address corresponding to thespecific data. Since the storage unit does not know the address of thespecific data, the storage unit sequentially outputs all data. Theexternal controller receives all data to determine whether the dataoutput from the storage unit is the specific data. Therefore, theexternal controller spends long time to find the specific data.

BRIEF SUMMARY OF THE INVENTION

In accordance with an embodiment, a storage unit is coupled to acontroller for receiving a first control signal and a second controlsignal and comprises a cell array, a first access module and a secondaccess module. The cell array stores data. The first access moduleaccesses the data stored in the cell array according to the firstcontrol signal. The second access module processes the data stored inthe cell array according to the second control signal to generate asearch result and provides the search result to the controller. When thefirst access module receives the first control signal and the secondaccess module receives the second control signal, the first and secondaccess modules simultaneously operate.

In accordance with another embodiment, a control system comprises acontroller and a storage unit. The controller sends a first controlsignal and a second control signal. The storage unit receives the firstand second control signals and comprises a cell array, a first accessmodule and a second access module. The cell array stores data. The firstaccess module accesses the data stored in the cell array according tothe first control signal. The second access module processes the datastored in the cell array according to the second control signal togenerate a search result and provides the search result to thecontroller. When the first access module receives the first controlsignal and the second access module receives the second control signal,the first and second access modules simultaneously operate.

A detailed description is given in the following embodiments withreference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be more fully understood by referring to the followingdetailed description and examples with references made to theaccompanying drawings, wherein:

FIGS. 1A and 1B are schematic diagrams of exemplary embodiments of acontrol system, in accordance with some embodiments; and

FIG. 2 is a schematic diagram of an exemplary embodiment of a storageunit, in accordance with some embodiments.

DETAILED DESCRIPTION OF THE INVENTION

The following description is of the best-contemplated mode of carryingout the invention. This description is made for the purpose ofillustrating the general principles of the invention and should not betaken in a limiting sense. The scope of the invention is best determinedby reference to the appended claims.

FIG. 1A is a schematic diagram of an exemplary embodiment of a controlsystem, in accordance with some embodiments. The control system 100Acomprises a storage unit 110A and a controller 120A. The controller 120Awrites data into the storage unit 110A or reads the data stored in thestorage unit 110A. In one embodiment, the controller 120A reads specificdata stored in the storage unit 110A. For example, assume that thecontroller 120A desires to read maximum data stored in the storage unit110A. In this case, the storage unit 110A processes the data stored inthe storage unit 110A according to a setting condition (e.g. the controlsignal ctr12) provided by the controller 120A to search the maximum datastored in the storage unit 110A and then provides the search result(e.g. rdat2) to the controller 120A.

In other embodiments, the controller 120A utilizes another settingcondition to retrieve minimum data stored in the storage unit 110A, anaverage or a distributed state of the values of the data stored in thestorage unit 110A. In one embodiment, when the storage unit 110Aprovides specific data to the controller 120A, the storage unit 110Aprovides the specific data together with an address corresponding to thespecific data to the controller 120A.

The invention does not limit the kind of storage unit 110A. In oneembodiment, the storage unit 110A is a non-volatile memory, such as astatic random access memory (SRAM). In other embodiments, the storageunit 110A is other types of non-volatile memory or volatile memory. Inthis embodiment, the storage unit 110A comprises access modules 111A,112A and a cell array 113A.

The access module 111A accesses the data stored in the cell array 113Aaccording to a control signal ctrl1. In one embodiment, the controlsignal ctrl1 comprises address information. The access module 111Aaccesses the cell array 113A according to the address information. Theinvention does not limit the circuit structure of the access module111A. Any circuit can serve as the access module 111A, as long as thecircuit is capable of accessing the cell array.

In one embodiment, access module 111A executes a write action or a readaction for the cell array 113A according to the control signal ctrl1.When the access module 111A executes the write action for the cell array113A, the access module 111A writes external data wdat1 into the cellarray 113A. In one embodiment, the access module 111A encodes theexternal data wdat1 and then stores the encoded result in the cell array113A. In another embodiment, when the access module 111A executes theread action, the access module 111A reads the data stored in the cellarray 113A and outputs read data rdat1 to the controller 120A.

The access module 112A processes the data stored in the cell array 113Aaccording to the control signal ctr12 to generate a search result rdat2and provides the search result rdat2 to the controller 120A. In oneembodiment, the control signal ctr12 may be the same as or differentfrom the control signal ctrl1. In other embodiments, the control signalctr12 is a setting condition. The access module 112A searches specificdata stored in the cell array 113A or processes the data stored in thecell array 113A to obtain an average value or a data distributed stateaccording to the control signal ctr12.

The invention does not limit the circuit structure of the access module112A. In one embodiment, the access module 112A utilizes a digitalmethod to read the data stored in the cell array 113A and executes asearch comparing action to obtain specific data. In other embodiments,any circuit can serve as the access module 112A, as long as the circuitis capable of processing the data stored in the cell array 113A.

In one embodiment, the access module 112A executes a convergencealgorithm to compare the data stored in the cell array 113A and thengenerates the search result rdat2 that indicates specific data, maximumdata or minimum data. In another embodiment, the access module 112Aprocesses the data stored in the cell array 113A to obtain an averagevalue or data distributed information. In other embodiments, the searchresult rdat2 comprises specific data and an address corresponding to thespecific data.

When the access module 111A executes a write action or a read action forthe cell array 113A, if the access module 112A receives the controlsignal ctr12, the access module 112A can simultaneously execute a readaction for the cell array 113A. Similarly, when the access module 112Aexecutes a read action for the cell array 113A, if the access module111A receives the control signal ctrl1, the access module 111A cansimultaneously execute a write action or a read action for the cellarray 113A. Therefore, the controller 120A not only obtains the datacorresponding to a specific address, but also obtains specificinformation stored in the cell array 113A.

In one embodiment, during a first period, the controller 120A sends thecontrol signal ctr12 to read the specific information stored in thestorage unit 110A. During a second period, the controller 120A operatesin a waiting mode. During this period, the controller 120A waits untilthe access module 112A generates a search result rdat2. The accessmodule 112A processes the data stored in the cell array 113A accordingto the control signal ctr12 to generate the search result rdat2. Duringa third period, the controller 120A receives the search result rdat2.

In one embodiment, during the second period, the controller 120A sendsthe control signal ctrl1. When the control signal ctrl1 relates to aread action, the access module 111A reads the cell array 113A accordingto the control signal ctrl1 during at least one of the second and thirdperiods. During at least one of the second and third periods, the accessmodule 111A outputs a read result rdat1 to the controller 120A. When thecontrol signal ctrl1 relates to a write action, the access module 111Awrites the external data wdat1 into the cell array 113A according to thecontrol signal ctrl1.

FIG. 1B is a schematic diagram of another exemplary embodiment of acontrol system, in accordance with some embodiments. In this embodiment,the access modules 111B and 112B encode the control signal ctrl togenerate an encoded result and then access the cell array 113B accordingto the encoded result. In one embodiment, when the encoded result is afirst state, it means that the controller 120B desires to write theexternal data wdat into the cell array 113B. Therefore, the accessmodule 111B writes the external data wdat into the cell array 113B.

In another embodiment, when the encoded result is a second state, itmeans that the controller 120B desires to read data corresponding to aspecific address within the cell array 113B. In this case, the accessmodule 111B reads the cell array 113B according to the specific addressand then provides the read data rdat to the controller 120B.

In other embodiments, when the encoded result is a third state, it meansthe controller 120B desires to read specific data stored in the cellarray 113B. Therefore, the access module 112B searches or processes thedata stored in the cell array 113B to generate a search result andserves the search result as the read data rdat to the controller 120B.

FIG. 2 is a schematic diagram of an exemplary embodiment of a storageunit, in accordance with some embodiments. The storage unit 200comprises access modules 210, 220 and a cell array 230. The inventiondoes not limit the circuit structure of the access module 210. In thisembodiment, the access module 210 comprises a selector 211, such as amultiplexer. The selector 211 is coupled to each bit cell within thecell array 230. The selector 211 writes external data wdat1 into thecell array 230 according to the control signal ctrl1. In anotherembodiment, the selector 211 reads the data stored in each bit cell ofthe cell array 230 according to the control signal ctrl1 and outputs aread result rdat1.

In this embodiment, the access module 220 comprises a comparing unit221, an operation unit 222 and a search table 223. The comparing unit221 encodes the control signal ctr12 to generate compared informationS_(M1). The operation unit 222 is coupled to the cell array 230 to readthe data stored in the cell array 230 and then processes the data storedin the cell array 230 according to the compared information S_(M1). Inone embodiment, the operation unit 222 comprises a plurality ofcomparators to compare the data stored in the cell array 230 withcompared information S_(M1) to obtain specific data, maximum data orminimum data.

In this embodiment, the operation unit 222 comprises a bit operationunit 224 and a bit processing unit 225. The bit operation unit 224processes the data stored in the cell array 230 according to thecompared information S_(M1). In one embodiment, the bit operation unit224 executes a convergence algorithm for the data stored in the cellarray 230. The bit processing unit 225 processes the operation resultsprovided by the bit operation unit 224 to generate processed results andstores the processed results into the search table 223. In oneembodiment, the search table 223 stores at least one of a data averagevalue, a data distributed state, specific data, maximum data, andminimum data.

An external controller (e.g. 120A or 120B) quickly obtains the specificdata according to information stored in the search table 223.Furthermore, the external controller provides a specific address suchthat the access module 210 reads the data stored in the cell array 230or writes external data into the cell array 230 according to thespecific address. Therefore, the storage unit 200 is capable ofproviding data corresponding to the specific address to the externalcontroller and is capable of providing the specific data to the externalcontroller according to a setting condition provided by the externalcontroller.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

While the invention has been described by way of example and in terms ofthe preferred embodiments, it is to be understood that the invention isnot limited to the disclosed embodiments. On the contrary, it isintended to cover various modifications and similar arrangements (aswould be apparent to those skilled in the art). Therefore, the scope ofthe appended claims should be accorded the broadest interpretation so asto encompass all such modifications and similar arrangements.

What is claimed is:
 1. A storage unit coupled to a controller forreceiving a first control signal and a second control signal,comprising: a cell array storing data; a first access module accessingthe data stored in the cell array according to the first control signal;and a second access module processing the data stored in the cell arrayaccording to the second control signal to generate a search result andproviding the search result to the controller, wherein when the firstaccess module receives the first control signal and the second accessmodule receives the second control signal, the first and second accessmodules simultaneously operate.
 2. The storage unit as claimed in claim1, wherein the first control signal equals the second control signal. 3.The storage unit as claimed in claim 1, wherein when the first andsecond access modules receive the first and second control signalsrespectively, the first access module receives external data accordingto the first control signal, encodes the external data to generateencoded data, and writes the encoded data into the cell array, and thesecond access module reads the cell array according to the secondcontrol signal.
 4. The storage unit as claimed in claim 1, wherein whenthe first and second access modules receive the first and second controlsignals respectively, the first access module reads the cell arrayaccording to the first control signal, and the second access modulereads the cell array according to the second control signal.
 5. Thestorage unit as claimed in claim 1, wherein during a first period, thecontroller sends the second control signal, during a second period, thecontroller sends the first control signal after the second access modulesends the search result, and during a third period, the controllerreceives the search result.
 6. The storage unit as claimed in claim 5,wherein during at least one of the second and third periods, the firstaccess module reads the cell array and sends a read result to thecontroller.
 7. The storage unit as claimed in claim 5, wherein during atleast one of the second and third periods, the controller providesexternal data, and the first access module writes the external data intothe cell array according to the first control signal.
 8. The storageunit as claimed in claim 1, wherein the second access module comprisesan operation unit processing the data stored in the cell array accordingto a convergence algorithm.
 9. The storage unit as claimed in claim 8,wherein the operation unit comprises a plurality of comparators forcomparing the data stored in the cell array.
 10. The storage unit asclaimed in claim 1, wherein the search result comprises search data andan address corresponding to the search data within the data stored inthe cell array.
 11. A control system comprising: a controller sending afirst control signal and a second control signal; and a storage unitreceiving the first and second control signals and comprising: a cellarray storing data; a first access module accessing the data stored inthe cell array according to the first control signal; and a secondaccess module processing the data stored in the cell array according tothe second control signal to generate a search result and providing thesearch result to the controller, wherein when the first and secondaccess modules receive the first and second control signalsrespectively, the first and second access modules simultaneouslyoperate.
 12. The control system as claimed in claim 11, wherein thefirst control signal equals the second control signal.
 13. The controlsystem as claimed in claim 11, wherein when the first and second accessmodules receive the first and second control signals respectively, thefirst access module receives external data according to the firstcontrol signal, encodes the external data to generate encoded data, andwrites the encoded data into the cell array, and the second accessmodule reads the cell array according to the second control signal. 14.The control system as claimed in claim 11, wherein when the first andsecond access modules receive the first and second control signalsrespectively, the first access module reads the cell array according tothe first control signal, and the second access module reads the cellarray according to the second control signal.
 15. The control system asclaimed in claim 11, wherein during a first period, the controller sendsthe second control signal, during a second period, the controller sendsthe first control signal after the second access module sends the searchresult, and during a third period, the controller receives the searchresult.
 16. The control system as claimed in claim 15, wherein during atleast one of the second and third periods, the first access module readsthe cell array and sends a read result to the controller.
 17. Thecontrol system as claimed in claim 15, wherein during at least one ofthe second and third periods, the controller provides external data, andthe first access module writes the external data into the cell arrayaccording to the first control signal.
 18. The control system as claimedin claim 11, wherein the second access module comprises an operationunit processing the data stored in the cell array according to aconvergence algorithm.
 19. The control system as claimed in claim 18,wherein the operation unit comprises a plurality of comparators forcomparing the data stored in the cell array.
 20. The control system asclaimed in claim 11, wherein the search result comprises search data andan address corresponding to the search data within the data stored inthe cell array, and the storage unit is a SRAM.